Hollow tubular blank provided in wall thereof with one or more reinforcing ribs

ABSTRACT

A hollow metal tubular blank is provided in the wall with one or more reinforcing ribs which are formed by extrusion of the wall. The reinforcing ribs have an inner ridge and an outer ridge. The reinforcing ribs serve to enhance the structural strength of a retaining slot which is formed in the reinforcing portion of the wall of the blank.

FIELD OF THE INVENTION

[0001] The present invention relates generally to a hollow tubular blank, and more particularly to a valve ball blank provided with one or more reinforcing ribs.

BACKGROUND OF THE INVENTION

[0002] As shown in FIG. 1, a hollow stainless steel or copper tube 1 of a specification is used as a blank to make a valve ball 3 by a molding tool 2 such that the tube 1 is formed into the valve ball 3 with two holes 31 by two die blocks 22, each having two die slots 21. The die slots 21 are provided with an arcuate wall 211. The valve ball 3 is provided with a retaining slot 32 by die forging. The retaining slot 32 is used to retain a valve rod.

[0003] Such a prior art tubular blank 1 as described above is defective in design in that the tubular blank 1 is not provided in the wall with a reinforcing structure which serves to increase the structural strength of the retaining slot 32 of the valve ball 3. As a result, the retaining slot 32 is susceptible to damage.

SUMMARY OF THE INVENTION

[0004] The primary objective of the present invention is to provide a metal tubular blank with one or more reinforcing ribs which are formed in a predetermined position of the wall of the metal tubular blank so as to facilitate the forming of a retaining slot. In other words, the retaining slot is formed by die forging in the reinforced portion of the wall of the tubular blank, thereby resulting in an increase in wall thickness of the retaining slot.

[0005] The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the present invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 shows a schematic process flow of a prior art valve ball.

[0007]FIG. 2 shows a schematic process flow of a valve ball blank of the present invention.

[0008]FIG. 3 shows a schematic process flow of a valve ball of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0009] As shown in FIG. 2, a hollow metal tube 4 of a specification is formed into a valve ball blank 6 by die forging a dieing machine 5 is used to form the valve ball blank 6. The dieing machine 5 has an upper mold 51, a lower mold 52, an upper die block 53, and. A lower die block 54. When the upper and the lower molds 51 and 52 are joined together with the upper and the lower die blocks 53 and 54, two arcuate recesses 55 are formed. The hollow metal tube 4 is disposed between the upper mold 51 and the lower mold 52. When the upper mold 51 is at work, both ends of the hollow metal tube 4 are under great pressure such that the walls of the both ends of the hollow metal tube 4 are extruded toward the arcuate recesses 55, thereby resulting in formation of two reinforcing ribs 61 opposite to each other. Each of the two reinforcing ribs 61 has an inner ridge 611 and an outer ridge 612.

[0010] The valve ball blank 6 of the present invention is provided with two reinforcing ribs 61, as shown in FIG. 2. The reinforcing ribs 61 of the valve ball blank 6 can be located at any desired location by adjusting the position of the arcuate recesses 55 of the dieing machine 5.

[0011] As show in FIG. 3, the valve ball blank 6 of the present invention is arranged between an upper mold 71 and a lower mold 72 of a forging machine 7. The upper mold 71 is provided with an arcuate slot 711 while the lower mold 72 is provided with an arcuate slot 721. As the valve ball blank 6 is pressed, the outer ridges 612 of the valve ball blank 6 are forced to deform by the arcuate surfaces of the arcuate slots 711 and 721, thereby resulting in an increase in thickness of the inner ridges 611. As a result, a valve ball 8 is formed such that the valve ball 8 is provided with two reinforcing ribs 81, and a retaining slot 82 which is corresponding in location to one of the two reinforcing ribs 81. The reinforcing rib 81 gives an added strength to the structure of the retaining slot 82.

[0012] The present invention described above is to be regarded in all respects as being illustrative and nonrestrictive. Accordingly, the present invention may be embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scopes of the following claims. 

What is claimed is:
 1. A hollow tubular blank made of a metal and provided in a predetermined position of a wall thereof with a reinforcing rib.
 2. The hollow tubular blank as defined in claim 1, wherein said reinforcing rib is formed by extrusion of the wall of one end of said metal tubular blank in a dieing machine whereby said reinforcing rib is formed of an inner ridge and an outer ridge.
 3. The hollow tubular blank as defined in claim 2, wherein said reinforcing rib can be formed in any position of the wall of said metal tubular blank by a design change in the dieing machine. 